Add The Ruby Toolbox (#416)

Author: fralps

helpers/the-ruby-toolbox.json

@@ -0,0 +1,12 @@
+{
+  "name": "The Ruby Toolbox",
+  "desc": "Find actively maintained & popular open source software libraries for the Ruby programming language",
+  "url": "https://www.ruby-toolbox.com/",
+  "tags": [
+    "Ruby"
+  ],
+  "maintainers": [
+    "colszowka"
+  ],
+  "addedAt": "2022-02-18"
+}